We address three main problems regarding the use of the traditionaldataflow language (TDL) for modelling large and dynamic networks:(1)The problem of scalability. The concepts and notations of TDL do not scale well. Thus TDL specifications may get large (space consuming) and chaotic.(2)The problem of generality. TDL does not have the expressibility for specifying networks consisting of n (a general number) components. We distinguish between five different network topologies consisting n components that can not be specified in TDL. For point-to-point networks these are the star, ring and tree topologies, for multipoint networks the ring and the bus topologies.(3)The problem of expressing dynamic reconfiguration. TDL is not well suited for the specification of dynamic networks. We distinguish between three kinds of dynamic networks: object-oriented networks, ad hoc networks, and mobile code networks.Based on an examination of three state-of-the-art modelling languages(FOCUS, SDL-2000 and UML 2.0), we propose a language, MEADOW(ModElling lAnguage for DataflOW) that essentially is an extension ofTDL. Our hypothesis is that MEADOW successfully solves the problemsmentioned above, and we argument by small examples and case studies.